<?php
//值传递
$v1 = 10;
$v2 = $v1;//这是传值
$v3 = $v1 +10;//这不是
echo "<br>v2=",$v2;
$v1 =11;
echo"<br>v2=",$v2;
echo "<br>";
//引用传递
$va = 1;
$vb = &$va;
echo "vb=",$vb;
$va = 2;
echo "<br>vb=",$vb;